Identification

Name
Diphenhydramine
Accession Number
DB01075  (APRD00587, DB06975)
Type
Small Molecule
Groups
Approved
Description

A histamine H1 antagonist used as an antiemetic, antitussive, for dermatoses and pruritus, for hypersensitivity reactions, as a hypnotic, an antiparkinson, and as an ingredient in common cold preparations. It has some undesired antimuscarinic and sedative effects.

Structure
Thumb
Synonyms
  • 2-(Benzhydryloxy)-N,N-dimethylethylamine
  • 2-diphenylmethoxy-N,N-demthylethanamine
  • alpha-(2-Dimethylaminoethoxy)diphenylmethane
  • beta-Dimethylaminoethanol diphenylmethyl ether
  • beta-Dimethylaminoethyl benzhydryl ether
  • Difenhidramina
  • Diphenhydraminum
  • N-(2-(Diphenylmethoxy)ethyl)-N,N-dimethylamine
  • O-benzhydryldimethylaminoethanol
  • β-dimethylaminoethyl benzhydryl ether
Product Ingredients
IngredientUNIICASInChI Key
Diphenhydramine citrate4OD433S20988637-37-0SPCKHVPPRJWQRZ-UHFFFAOYSA-N
Diphenhydramine hydrochlorideTC2D6JAD40147-24-0PCHPORCSPXIHLZ-UHFFFAOYSA-N
Diphenhydramine methylbromideUJO67AO8YI31065-89-1BDQPXVWYFLTETB-UHFFFAOYSA-M
Diphenhydramine salicylate707L3YC54L7491-10-3RTSZUSOHOIFYSY-UHFFFAOYSA-N
Product Images
Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Benadryl Inj. 50mg/mlLiquid50 mgIntramuscular; IntravenousWarner Lambert Canada Inc.1994-12-312000-11-27Canada
Diphenhydramine HCl Inj USP 50mg/mlLiquid50 mgIntravenousInternational Medication Systems, Limited1974-12-311997-08-15Canada
Diphenhydramine HCl Injection, USPSolution50 mgIntramuscular; IntravenousSterimax Inc1994-12-31Not applicableCanada
Diphenhydramine Hydrochloride InjectionSolution50 mgIntramuscular; IntravenousFresenius Kabi2012-02-17Not applicableCanada
Diphenhydramine Hydrochloride Injection USPLiquid50 mgIntramuscular; IntravenousSandoz Canada Incorporated1983-12-31Not applicableCanada
Diphenist 50mg/mlLiquid50 mgIntramuscular; IntravenousOmega Laboratories Ltd1997-10-28Not applicableCanada
PMS-diphenhydramine Hydrochloride Inj 50mg/mlLiquid50 mgIntramuscular; IntravenousPharmascience Inc1991-12-31Not applicableCanada
Scheinpharm Diphenhydramine Inj.50mg/mlSolution50 mgIntramuscular; IntravenousSchein Pharmaceutical Canada Inc.1996-09-302004-07-26Canada
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Diphendydramine HydrochlorideCapsule25 mg/1OralRemedy Repack2010-12-172017-06-20Us66424 0020 01 nlmimage10 1a038d6c
DiphenhydramineInjection, solution50 mg/mLIntramuscular; IntravenousAPP Pharmaceuticals, Inc.2002-08-01Not applicableUs
DiphenhydramineInjection, solution50 mg/mLIntravenousRemedy Repack2013-06-132017-01-24Us
Diphenhydramine HydrochlorideInjection50 mg/mLIntramuscular; IntravenousRebel Distributors1972-11-27Not applicableUs
Diphenhydramine HydrochlorideInjection50 mg/mLIntramuscular; IntravenousCardinal Health2002-05-28Not applicableUs
Diphenhydramine HydrochlorideCapsule50 mg/1OralContract Pharmacy Services Pa2010-08-05Not applicableUs00555 0059 02 nlmimage10 a62dd30e
Diphenhydramine HydrochlorideSolution12.5 mg/5mLOralPharmaceutical Associates, Inc.1982-02-10Not applicableUs
Diphenhydramine HydrochlorideInjection50 mg/mLIntramuscular; IntravenousRemedy Repack2017-01-06Not applicableUs
Diphenhydramine HydrochlorideInjection, solution50 mg/mLIntramuscular; IntravenousGeneral Injectables & Vaccines2010-03-01Not applicableUs
Diphenhydramine HydrochlorideInjection, solution50 mg/mLIntramuscular; IntravenousGeneral Injectables & Vaccines2010-07-01Not applicableUs
Over the Counter Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
7 Select AllergyTablet25 mg/1Oral7 Eleven2014-04-22Not applicableUs
7 Select Allergy ChildrensSolution12.5 mg/5mLOral7 Eleven2014-08-05Not applicableUs
7 Select Night Time Sleep AidLiquid50 mg/30mLOral7 Eleven2014-04-22Not applicableUs
Adult AllergySolution50 mg/20mLOralChain Drug Consortium2015-05-04Not applicableUs
Adult Allergy ReliefSolution50 mg/20mLOralWalmart Stores2017-05-03Not applicableUs
After Bite OutdoorGel20 mg/mLTopicalTender Corporation2016-11-01Not applicableUs
After Bite PlusCream20 mg/mLTopicalTender Corporation2012-07-03Not applicableUs
After Bite XtraGel20 mg/mLTopicalTender Corporation2016-11-01Not applicableUs
After StingGel20 mg/mLTopicalTender Corporation2016-11-01Not applicableUs
AfterBite with AntihistimineCream2 mL/100mLTopicalTender Corporation2012-07-032016-11-03Us
Unapproved/Other Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
DicopanolKitOralFusion Pharmaceuticals LLC2010-02-08Not applicableUs
DicopanolKitOralCalifornia Pharmaceuticals, Llc2016-01-01Not applicableUs
Diphenhydramine HClCapsule25 mg/1OralCardinal Health2011-06-032017-07-18Us
Diphenhydramine HClCapsule, liquid filled50 mg/1OralAi Ping Pharmaceutical, Inc.2015-01-31Not applicableUs
Diphenhydramine HClTablet25 mg/1OralCardinal Health2011-06-03Not applicableUs
Diphenhydramine HydrochlorideTablet50 mg/1OralAdvance Pharmaceutical Inc.2012-09-01Not applicableUs
International/Other Brands
Aleryl / Alledryl / Allerdryl (Valeant) / Baramine / Beldin / Belix / Benylan (Biogen) / Dermodrin (Montavit) / Desentol (Meda) / Dibondrin (Montavit) / Dimedrol (Zdorovie) / Diphen (Wockhardt) / Dormarex 2 / Genahist / Histaxin (Meda) / Hyrexin (Hyrex) / Nytol Quickgels (GlaxoSmithKline) / Restamin (Kowa Souyaku) / Siladryl / Silphen Cough
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing End
7 Select Ibuprofen PMDiphenhydramine citrate (38 mg/1) + Ibuprofen (200 mg/1)Tablet, coatedOral7 Eleven2014-08-05Not applicableUs
7 Select Night Time Severe Cold Cough and FluDiphenhydramine hydrochloride (25 mg/1) + Acetaminophen (650 mg/1) + Phenylephrine hydrochloride (10 mg/1)Powder, for solutionOral7 Eleven2016-01-25Not applicableUs
7 Select Night Time severe cold, cough and fluDiphenhydramine hydrochloride (25 mg/1) + Acetaminophen (650 mg/1) + Phenylephrine hydrochloride (10 mg/1)Powder, for solutionOral7 Eleven2015-11-12Not applicableUs
7 Select Pain Relief PMDiphenhydramine hydrochloride (25 mg/1) + Acetaminophen (500 mg/1)Tablet, film coatedOral7 Eleven2014-09-04Not applicableUs
7-Select Advil PMDiphenhydramine citrate (38 mg/1) + Ibuprofen (200 mg/1)Tablet, coatedOralLil' Drug Store Products, Inc.2011-06-01Not applicableUs
Aceta-gesicDiphenhydramine hydrochloride (12.5 mg/1) + Acetaminophen (325 mg/1)Tablet, coatedOralRemedy Repack2014-08-08Not applicableUs
Aceta-gesicDiphenhydramine hydrochloride (12.5 mg/1) + Acetaminophen (325 mg/1)Tablet, coatedOralRugby2014-06-30Not applicableUs
AcetadrylDiphenhydramine hydrochloride (25 mg/1) + Acetaminophen (500 mg/1)Tablet, film coatedOralAidarex Pharmaceuticals LLC2011-07-21Not applicableUs
AcetadrylDiphenhydramine hydrochloride (25 mg/1) + Acetaminophen (500 mg/1)Tablet, film coatedOralPhysicians Science & Nature Inc.2011-07-21Not applicableUs
Acetaminophen / Diphenhydramine 500/25 mgDiphenhydramine hydrochloride (25 mg/1) + Acetaminophen (500 mg/1)TabletOralReliable 1 Laboratories2015-11-01Not applicableUs
Categories
UNII
8GTS82S83M
CAS number
58-73-1
Weight
Average: 255.3547
Monoisotopic: 255.162314299
Chemical Formula
C17H21NO
InChI Key
ZZVUWRFHKOJYTH-UHFFFAOYSA-N
InChI
InChI=1S/C17H21NO/c1-18(2)13-14-19-17(15-9-5-3-6-10-15)16-11-7-4-8-12-16/h3-12,17H,13-14H2,1-2H3
IUPAC Name
[2-(diphenylmethoxy)ethyl]dimethylamine
SMILES
CN(C)CCOC(C1=CC=CC=C1)C1=CC=CC=C1

Pharmacology

Indication

For the treatment of symptoms associated with Vertigo/Meniere's disease, nausea and vomiting, motion sickness and insect bite.

Structured Indications
Pharmacodynamics

Diphenhydramine is an antihistamine of the ethanolamine class. Ethanolamine antihistamines have significant antimuscarinic activity and produce marked sedation in most patients. In addition to the usual allergic symptoms, the drug also treats irritant cough and nausea, vomiting, and vertigo associated with motion sickness. It also is used commonly to treat drug-induced extrapyramidal symptoms as well as to treat mild cases of Parkinson's disease. Rather than preventing the release of histamine, as do cromolyn and nedocromil, diphenhydramine competes with free histamine for binding at HA-receptor sites. Diphenhydramine competitively antagonizes the effects of histamine on HA-receptors in the GI tract, uterus, large blood vessels, and bronchial muscle. Ethanolamine derivatives have greater anticholinergic activity than do other antihistamines, which probably accounts for the antidyskinetic action of diphenhydramine. This anticholinergic action appears to be due to a central antimuscarinic effect, which also may be responsible for its antiemetic effects, although the exact mechanism is unknown.

Mechanism of action

Diphenhydramine competes with free histamine for binding at HA-receptor sites. This antagonizes the effects of histamine on HA-receptors, leading to a reduction of the negative symptoms brought on by histamine HA-receptor binding.

TargetActionsOrganism
AHistamine H1 receptor
antagonist
Human
UMuscarinic acetylcholine receptor M2
antagonist
Human
Absorption

Quickly absorbed with maximum activity occurring in approximately one hour.

Volume of distribution
Not Available
Protein binding

98 to 99%

Metabolism

Hepatic and renal

Route of elimination

Little, if any, is excreted unchanged in the urine; most appears as the degradation products of metabolic transformation in the liver, which are almost completely excreted within 24 hours.

Half life

1-4 hours

Clearance
Not Available
Toxicity

LD50=500 mg/kg (orally in rats). Considerable overdosage can lead to myocardial infarction (heart attack), serious ventricular dysrhythmias, coma and death.

Affected organisms
  • Humans and other mammals
Pathways
PathwayCategory
Diphenhydramine H1-Antihistamine ActionDrug action
Pharmacogenomic Effects/ADRs
Not Available

Interactions

Drug Interactions
DrugInteractionDrug group
2,5-Dimethoxy-4-ethylamphetamine2,5-Dimethoxy-4-ethylamphetamine may decrease the sedative activities of Diphenhydramine.Experimental, Illicit
3,4-Methylenedioxyamphetamine3,4-Methylenedioxyamphetamine may decrease the sedative activities of Diphenhydramine.Experimental, Illicit
4-Bromo-2,5-dimethoxyamphetamine4-Bromo-2,5-dimethoxyamphetamine may decrease the sedative activities of Diphenhydramine.Experimental, Illicit
4-MethoxyamphetamineThe metabolism of 4-Methoxyamphetamine can be decreased when combined with Diphenhydramine.Experimental, Illicit
7-NitroindazoleThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with 7-Nitroindazole.Experimental
AbirateroneThe serum concentration of Diphenhydramine can be increased when it is combined with Abiraterone.Approved
AcepromazineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Acepromazine.Approved, Vet Approved
AceprometazineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Aceprometazine.Approved
AcetaminophenThe metabolism of Acetaminophen can be decreased when combined with Diphenhydramine.Approved
AcetylcholineThe metabolism of Acetylcholine can be decreased when combined with Diphenhydramine.Approved
AdipiplonThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Adipiplon.Investigational
AgomelatineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Agomelatine.Approved, Investigational
AjmalineThe metabolism of Ajmaline can be decreased when combined with Diphenhydramine.Approved, Investigational
AlaproclateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Alaproclate.Experimental
AlfaxaloneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Alfaxalone.Vet Approved
AlfentanilThe risk or severity of adverse effects can be increased when Alfentanil is combined with Diphenhydramine.Approved, Illicit
AllopregnanoloneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Allopregnanolone.Investigational
AlmotriptanThe metabolism of Almotriptan can be decreased when combined with Diphenhydramine.Approved, Investigational
AlogliptinThe metabolism of Alogliptin can be decreased when combined with Diphenhydramine.Approved
AlphacetylmethadolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Alphacetylmethadol.Experimental, Illicit
AlphaprodineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Alphaprodine.Illicit
AlprazolamThe risk or severity of adverse effects can be increased when Alprazolam is combined with Diphenhydramine.Approved, Illicit, Investigational
AlprenololThe metabolism of Alprenolol can be decreased when combined with Diphenhydramine.Approved, Withdrawn
AminophenazoneThe metabolism of Aminophenazone can be decreased when combined with Diphenhydramine.Approved, Withdrawn
AmiodaroneDiphenhydramine may increase the QTc-prolonging activities of Amiodarone.Approved, Investigational
AmisulprideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Amisulpride.Approved, Investigational
AmitriptylineThe metabolism of Amitriptyline can be decreased when combined with Diphenhydramine.Approved
AmobarbitalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Amobarbital.Approved, Illicit
AmoxapineThe metabolism of Amoxapine can be decreased when combined with Diphenhydramine.Approved
AmperozideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Amperozide.Experimental
AmphetamineThe metabolism of Amphetamine can be decreased when combined with Diphenhydramine.Approved, Illicit
AmprenavirThe metabolism of Amprenavir can be decreased when combined with Diphenhydramine.Approved
AmsacrineThe metabolism of Amsacrine can be decreased when combined with Diphenhydramine.Approved
AnagrelideDiphenhydramine may increase the QTc-prolonging activities of Anagrelide.Approved
AntipyrineThe metabolism of Antipyrine can be decreased when combined with Diphenhydramine.Approved
AprepitantThe metabolism of Diphenhydramine can be increased when combined with Aprepitant.Approved, Investigational
AprindineThe metabolism of Aprindine can be decreased when combined with Diphenhydramine.Approved
ArformoterolThe metabolism of Arformoterol can be decreased when combined with Diphenhydramine.Approved, Investigational
AripiprazoleThe serum concentration of Aripiprazole can be increased when it is combined with Diphenhydramine.Approved, Investigational
ArmodafinilThe metabolism of Diphenhydramine can be decreased when combined with Armodafinil.Approved, Investigational
Arsenic trioxideDiphenhydramine may increase the QTc-prolonging activities of Arsenic trioxide.Approved, Investigational
ArtemetherDiphenhydramine may increase the QTc-prolonging activities of Artemether.Approved
ArticaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Articaine.Approved
AsenapineDiphenhydramine may increase the QTc-prolonging activities of Asenapine.Approved
AstemizoleThe metabolism of Astemizole can be decreased when combined with Diphenhydramine.Approved, Withdrawn
AtomoxetineThe metabolism of Diphenhydramine can be decreased when combined with Atomoxetine.Approved
AzaperoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Azaperone.Investigational, Vet Approved
AzelastineDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Azelastine.Approved
AzithromycinDiphenhydramine may increase the QTc-prolonging activities of Azithromycin.Approved
BaclofenThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Baclofen.Approved
BarbitalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Barbital.Illicit
BedaquilineDiphenhydramine may increase the QTc-prolonging activities of Bedaquiline.Approved
BenperidolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Benperidol.Investigational
BenzatropineThe metabolism of Benzatropine can be decreased when combined with Diphenhydramine.Approved
BenzocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Benzocaine.Approved
BenzphetamineBenzphetamine may decrease the sedative activities of Diphenhydramine.Approved, Illicit
Benzyl alcoholThe metabolism of Benzyl alcohol can be decreased when combined with Diphenhydramine.Approved
Benzylpenicilloyl PolylysineDiphenhydramine may decrease effectiveness of Benzylpenicilloyl Polylysine as a diagnostic agent.Approved
BepridilThe metabolism of Bepridil can be decreased when combined with Diphenhydramine.Approved, Withdrawn
BetahistineThe therapeutic efficacy of Betahistine can be decreased when used in combination with Diphenhydramine.Approved
BetaxololThe metabolism of Diphenhydramine can be decreased when combined with Betaxolol.Approved
BisoprololThe metabolism of Bisoprolol can be decreased when combined with Diphenhydramine.Approved
BortezomibThe metabolism of Diphenhydramine can be decreased when combined with Bortezomib.Approved, Investigational
BrexpiprazoleThe serum concentration of Brexpiprazole can be increased when it is combined with Diphenhydramine.Approved
BrimonidineBrimonidine may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved
BromazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Bromazepam.Approved, Illicit
BromisovalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Bromisoval.Experimental
BromperidolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Bromperidol.Investigational
BrompheniramineThe metabolism of Brompheniramine can be decreased when combined with Diphenhydramine.Approved
BrotizolamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Brotizolam.Approved, Investigational, Withdrawn
BufuralolThe metabolism of Bufuralol can be decreased when combined with Diphenhydramine.Experimental, Investigational
BupivacaineThe metabolism of Bupivacaine can be decreased when combined with Diphenhydramine.Approved, Investigational
BuprenorphineDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Buprenorphine.Approved, Illicit, Investigational, Vet Approved
BupropionThe metabolism of Diphenhydramine can be decreased when combined with Bupropion.Approved
BuspironeThe metabolism of Buspirone can be decreased when combined with Diphenhydramine.Approved, Investigational
ButabarbitalThe risk or severity of adverse effects can be increased when Butabarbital is combined with Diphenhydramine.Approved, Illicit
ButacaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Butacaine.Vet Approved
ButalbitalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Butalbital.Approved, Illicit
ButambenThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Butamben.Approved
ButethalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Butethal.Approved, Illicit
ButorphanolThe risk or severity of adverse effects can be increased when Butorphanol is combined with Diphenhydramine.Approved, Illicit, Vet Approved
CaffeineThe metabolism of Diphenhydramine can be decreased when combined with Caffeine.Approved
CanertinibThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Canertinib.Investigational
CapecitabineThe metabolism of Diphenhydramine can be decreased when combined with Capecitabine.Approved, Investigational
CaptoprilThe metabolism of Captopril can be decreased when combined with Diphenhydramine.Approved
CarbamazepineThe metabolism of Diphenhydramine can be increased when combined with Carbamazepine.Approved, Investigational
CarbinoxamineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Carbinoxamine.Approved
CarfentanilThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Carfentanil.Illicit, Investigational, Vet Approved
CariprazineThe metabolism of Cariprazine can be decreased when combined with Diphenhydramine.Approved
CarisoprodolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Carisoprodol.Approved
CarteololThe metabolism of Carteolol can be decreased when combined with Diphenhydramine.Approved
CarvedilolThe metabolism of Carvedilol can be decreased when combined with Diphenhydramine.Approved, Investigational
CelecoxibThe metabolism of Diphenhydramine can be decreased when combined with Celecoxib.Approved, Investigational
CephalexinThe metabolism of Cephalexin can be decreased when combined with Diphenhydramine.Approved, Vet Approved
CeritinibThe serum concentration of Diphenhydramine can be increased when it is combined with Ceritinib.Approved
CetirizineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Cetirizine.Approved
CevimelineThe metabolism of Cevimeline can be decreased when combined with Diphenhydramine.Approved
Chloral hydrateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Chloral hydrate.Approved, Illicit, Vet Approved
ChloramphenicolThe metabolism of Diphenhydramine can be decreased when combined with Chloramphenicol.Approved, Vet Approved
ChlordiazepoxideThe metabolism of Chlordiazepoxide can be decreased when combined with Diphenhydramine.Approved, Illicit
ChlormezanoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Chlormezanone.Approved, Investigational, Withdrawn
ChloroprocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Chloroprocaine.Approved
ChloroquineDiphenhydramine may increase the QTc-prolonging activities of Chloroquine.Approved, Vet Approved
ChlorphenamineThe metabolism of Chlorphenamine can be decreased when combined with Diphenhydramine.Approved
ChlorphentermineChlorphentermine may decrease the sedative activities of Diphenhydramine.Illicit, Withdrawn
ChlorpromazineDiphenhydramine may increase the QTc-prolonging activities of Chlorpromazine.Approved, Vet Approved
ChlorprothixeneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Chlorprothixene.Approved, Investigational, Withdrawn
ChlorzoxazoneThe metabolism of Chlorzoxazone can be decreased when combined with Diphenhydramine.Approved
CholecalciferolThe metabolism of Diphenhydramine can be decreased when combined with Cholecalciferol.Approved, Nutraceutical
CilostazolThe metabolism of Cilostazol can be decreased when combined with Diphenhydramine.Approved
CimetidineThe metabolism of Diphenhydramine can be decreased when combined with Cimetidine.Approved
CinacalcetThe metabolism of Diphenhydramine can be decreased when combined with Cinacalcet.Approved
CinchocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Cinchocaine.Approved, Vet Approved
CinnarizineThe metabolism of Cinnarizine can be decreased when combined with Diphenhydramine.Approved, Investigational
CiprofloxacinDiphenhydramine may increase the QTc-prolonging activities of Ciprofloxacin.Approved, Investigational
CisaprideDiphenhydramine may increase the QTc-prolonging activities of Cisapride.Approved, Investigational, Withdrawn
CitalopramDiphenhydramine may increase the QTc-prolonging activities of Citalopram.Approved
ClarithromycinDiphenhydramine may increase the QTc-prolonging activities of Clarithromycin.Approved
ClemastineThe metabolism of Diphenhydramine can be decreased when combined with Clemastine.Approved
ClevidipineThe metabolism of Clevidipine can be decreased when combined with Diphenhydramine.Approved
ClidiniumThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Clidinium.Approved
ClobazamThe metabolism of Diphenhydramine can be decreased when combined with Clobazam.Approved, Illicit
clomethiazoleThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with clomethiazole.Investigational
ClomipramineThe metabolism of Diphenhydramine can be decreased when combined with Clomipramine.Approved, Vet Approved
ClonazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Clonazepam.Approved, Illicit
ClonidineThe metabolism of Clonidine can be decreased when combined with Diphenhydramine.Approved
ClopenthixolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Clopenthixol.Experimental
ClopidogrelThe metabolism of Diphenhydramine can be decreased when combined with Clopidogrel.Approved, Nutraceutical
ClorazepateThe risk or severity of adverse effects can be increased when Clorazepate is combined with Diphenhydramine.Approved, Illicit
ClothiapineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Clothiapine.Experimental
ClotrimazoleThe metabolism of Diphenhydramine can be decreased when combined with Clotrimazole.Approved, Vet Approved
ClozapineDiphenhydramine may increase the QTc-prolonging activities of Clozapine.Approved
CobicistatThe serum concentration of Diphenhydramine can be increased when it is combined with Cobicistat.Approved
CocaineThe metabolism of Diphenhydramine can be decreased when combined with Cocaine.Approved, Illicit
CodeineThe therapeutic efficacy of Codeine can be decreased when used in combination with Diphenhydramine.Approved, Illicit
CrisaboroleThe metabolism of Diphenhydramine can be decreased when combined with Crisaborole.Approved
CrizotinibDiphenhydramine may increase the QTc-prolonging activities of Crizotinib.Approved
CyclizineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Cyclizine.Approved
CyclobenzaprineThe metabolism of Cyclobenzaprine can be decreased when combined with Diphenhydramine.Approved
CyclophosphamideThe metabolism of Cyclophosphamide can be decreased when combined with Diphenhydramine.Approved, Investigational
CyclosporineThe metabolism of Diphenhydramine can be decreased when combined with Cyclosporine.Approved, Investigational, Vet Approved
CyproheptadineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Cyproheptadine.Approved
Cyproterone acetateThe serum concentration of Diphenhydramine can be decreased when it is combined with Cyproterone acetate.Approved, Investigational
DabrafenibThe serum concentration of Diphenhydramine can be decreased when it is combined with Dabrafenib.Approved
DantroleneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dantrolene.Approved
DapagliflozinThe metabolism of Dapagliflozin can be decreased when combined with Diphenhydramine.Approved
DapiprazoleThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dapiprazole.Approved
DapoxetineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dapoxetine.Investigational
DarifenacinThe metabolism of Diphenhydramine can be decreased when combined with Darifenacin.Approved, Investigational
DarunavirThe serum concentration of Diphenhydramine can be increased when it is combined with Darunavir.Approved
DasabuvirThe metabolism of Dasabuvir can be decreased when combined with Diphenhydramine.Approved
DebrisoquinThe metabolism of Debrisoquin can be decreased when combined with Diphenhydramine.Approved, Investigational
DeferasiroxThe serum concentration of Diphenhydramine can be increased when it is combined with Deferasirox.Approved, Investigational
DelavirdineThe metabolism of Diphenhydramine can be decreased when combined with Delavirdine.Approved
DeramciclaneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Deramciclane.Investigational
DesfluraneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Desflurane.Approved
DesipramineThe metabolism of Diphenhydramine can be decreased when combined with Desipramine.Approved
DesloratadineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Desloratadine.Approved, Investigational
DesvenlafaxineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Desvenlafaxine.Approved
DetomidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Detomidine.Vet Approved
DeutetrabenazineThe metabolism of Deutetrabenazine can be decreased when combined with Diphenhydramine.Approved, Investigational
DexbrompheniramineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dexbrompheniramine.Approved
Dexchlorpheniramine maleateThe metabolism of Dexchlorpheniramine maleate can be decreased when combined with Diphenhydramine.Approved
DexfenfluramineThe metabolism of Dexfenfluramine can be decreased when combined with Diphenhydramine.Approved, Illicit, Investigational, Withdrawn
DexmedetomidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dexmedetomidine.Approved, Vet Approved
DexmethylphenidateThe metabolism of Dexmethylphenidate can be decreased when combined with Diphenhydramine.Approved
DextroamphetamineThe metabolism of Dextroamphetamine can be decreased when combined with Diphenhydramine.Approved, Illicit
DextromethorphanThe metabolism of Dextromethorphan can be decreased when combined with Diphenhydramine.Approved
DextromoramideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dextromoramide.Experimental, Illicit
DextropropoxypheneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dextropropoxyphene.Approved, Illicit, Investigational, Withdrawn
DezocineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dezocine.Approved, Investigational
DiazepamThe risk or severity of adverse effects can be increased when Diazepam is combined with Diphenhydramine.Approved, Illicit, Vet Approved
Diethyl etherThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Diethyl ether.Experimental
DiethylpropionDiethylpropion may decrease the sedative activities of Diphenhydramine.Approved, Illicit
DifenoxinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Difenoxin.Approved, Illicit
DihydrocodeineThe metabolism of Dihydrocodeine can be decreased when combined with Diphenhydramine.Approved, Illicit
DihydroetorphineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dihydroetorphine.Experimental, Illicit
DihydromorphineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dihydromorphine.Experimental, Illicit
DiltiazemThe metabolism of Diltiazem can be decreased when combined with Diphenhydramine.Approved
DimenhydrinateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dimenhydrinate.Approved
DiphenoxylateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Diphenoxylate.Approved, Illicit
DisopyramideDiphenhydramine may increase the QTc-prolonging activities of Disopyramide.Approved
DixyrazineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dixyrazine.Experimental
DofetilideDiphenhydramine may increase the QTc-prolonging activities of Dofetilide.Approved
DolasetronDiphenhydramine may increase the QTc-prolonging activities of Dolasetron.Approved
DomperidoneDiphenhydramine may increase the QTc-prolonging activities of Domperidone.Approved, Investigational, Vet Approved
DonepezilThe metabolism of Donepezil can be decreased when combined with Diphenhydramine.Approved
DopamineThe metabolism of Dopamine can be decreased when combined with Diphenhydramine.Approved
DoramectinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Doramectin.Vet Approved
DosulepinThe metabolism of Diphenhydramine can be decreased when combined with Dosulepin.Approved
DoxazosinThe metabolism of Doxazosin can be decreased when combined with Diphenhydramine.Approved
DoxepinThe metabolism of Doxepin can be decreased when combined with Diphenhydramine.Approved
DoxorubicinThe serum concentration of Doxorubicin can be increased when it is combined with Diphenhydramine.Approved, Investigational
DoxorubicinThe metabolism of Doxorubicin can be decreased when combined with Diphenhydramine.Approved, Investigational
DoxylamineDoxylamine may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved, Vet Approved
DPDPEThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with DPDPE.Investigational
DronabinolDronabinol may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved, Illicit
DronedaroneDiphenhydramine may increase the QTc-prolonging activities of Dronedarone.Approved
DroperidolDroperidol may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved, Vet Approved
DrotebanolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Drotebanol.Experimental, Illicit
DuloxetineThe metabolism of Diphenhydramine can be decreased when combined with Duloxetine.Approved
DyclonineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dyclonine.Approved
EcgonineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ecgonine.Experimental, Illicit
EcopipamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ecopipam.Investigational
EfavirenzThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Efavirenz.Approved, Investigational
EletriptanThe metabolism of Eletriptan can be decreased when combined with Diphenhydramine.Approved, Investigational
EliglustatThe serum concentration of Eliglustat can be increased when it is combined with Diphenhydramine.Approved
EltanoloneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Eltanolone.Investigational
EnasidenibThe metabolism of Enasidenib can be decreased when combined with Diphenhydramine.Approved
EncainideThe metabolism of Encainide can be decreased when combined with Diphenhydramine.Approved, Investigational, Withdrawn
EnclomipheneThe metabolism of Enclomiphene can be decreased when combined with Diphenhydramine.Investigational
EnfluraneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Enflurane.Approved, Investigational, Vet Approved
EntacaponeThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Entacapone.Approved, Investigational
EpinastineThe metabolism of Epinastine can be decreased when combined with Diphenhydramine.Approved, Investigational
ErlotinibThe metabolism of Erlotinib can be decreased when combined with Diphenhydramine.Approved, Investigational
ErythromycinDiphenhydramine may increase the QTc-prolonging activities of Erythromycin.Approved, Vet Approved
EscitalopramDiphenhydramine may increase the QTc-prolonging activities of Escitalopram.Approved, Investigational
Eslicarbazepine acetateThe metabolism of Diphenhydramine can be decreased when combined with Eslicarbazepine acetate.Approved
EsmirtazapineThe metabolism of Esmirtazapine can be decreased when combined with Diphenhydramine.Investigational
EsomeprazoleThe metabolism of Diphenhydramine can be decreased when combined with Esomeprazole.Approved, Investigational
EstazolamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Estazolam.Approved, Illicit
EszopicloneThe risk or severity of adverse effects can be increased when Eszopiclone is combined with Diphenhydramine.Approved
EthanolDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Ethanol.Approved
EthchlorvynolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ethchlorvynol.Approved, Illicit, Withdrawn
EthosuximideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ethosuximide.Approved
EthotoinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ethotoin.Approved
Ethyl carbamateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ethyl carbamate.Withdrawn
Ethyl chlorideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ethyl chloride.Experimental, Investigational
Ethyl loflazepateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ethyl loflazepate.Approved, Illicit
EthylmorphineThe metabolism of Ethylmorphine can be decreased when combined with Diphenhydramine.Approved, Illicit
EtidocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Etidocaine.Approved
EtifoxineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Etifoxine.Investigational, Withdrawn
EtizolamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Etizolam.Approved
EtomidateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Etomidate.Approved
EtoperidoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Etoperidone.Withdrawn
EtoricoxibThe metabolism of Etoricoxib can be decreased when combined with Diphenhydramine.Approved, Investigational
EtorphineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Etorphine.Illicit, Vet Approved
EtravirineThe metabolism of Diphenhydramine can be decreased when combined with Etravirine.Approved
EzogabineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ezogabine.Approved
FelbamateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Felbamate.Approved
FencamfamineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fencamfamine.Approved, Illicit, Withdrawn
FentanylThe risk or severity of adverse effects can be increased when Fentanyl is combined with Diphenhydramine.Approved, Illicit, Investigational, Vet Approved
FesoterodineThe serum concentration of the active metabolites of Fesoterodine can be increased when Fesoterodine is used in combination with Diphenhydramine.Approved
FexofenadineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fexofenadine.Approved
FingolimodThe metabolism of Fingolimod can be decreased when combined with Diphenhydramine.Approved, Investigational
FlecainideDiphenhydramine may increase the QTc-prolonging activities of Flecainide.Approved, Withdrawn
FlibanserinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Flibanserin.Approved
FloxuridineThe metabolism of Diphenhydramine can be decreased when combined with Floxuridine.Approved
FluanisoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fluanisone.Experimental
FluconazoleThe metabolism of Diphenhydramine can be decreased when combined with Fluconazole.Approved
FludiazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fludiazepam.Approved, Illicit
FlunarizineThe metabolism of Flunarizine can be decreased when combined with Diphenhydramine.Approved
FlunitrazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Flunitrazepam.Approved, Illicit
FluorouracilThe metabolism of Diphenhydramine can be decreased when combined with Fluorouracil.Approved
FluoxetineDiphenhydramine may increase the QTc-prolonging activities of Fluoxetine.Approved, Vet Approved
FlupentixolDiphenhydramine may increase the QTc-prolonging activities of Flupentixol.Approved, Withdrawn
FluphenazineThe metabolism of Fluphenazine can be decreased when combined with Diphenhydramine.Approved
FlurazepamThe risk or severity of adverse effects can be increased when Flurazepam is combined with Diphenhydramine.Approved, Illicit
FluspirileneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fluspirilene.Approved, Investigational
Fluticasone propionateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fluticasone propionate.Approved
FluvastatinThe metabolism of Fluvastatin can be decreased when combined with Diphenhydramine.Approved
FluvoxamineThe metabolism of Diphenhydramine can be decreased when combined with Fluvoxamine.Approved, Investigational
FormoterolThe metabolism of Formoterol can be decreased when combined with Diphenhydramine.Approved, Investigational
FosphenytoinThe metabolism of Diphenhydramine can be increased when combined with Fosphenytoin.Approved
FospropofolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fospropofol.Approved, Illicit, Investigational
GabapentinThe risk or severity of adverse effects can be increased when Gabapentin is combined with Diphenhydramine.Approved, Investigational
Gabapentin EnacarbilThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Gabapentin Enacarbil.Approved
Gadobenic acidDiphenhydramine may increase the QTc-prolonging activities of Gadobenic acid.Approved
GalantamineThe metabolism of Galantamine can be decreased when combined with Diphenhydramine.Approved
Gamma Hydroxybutyric AcidThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Gamma Hydroxybutyric Acid.Approved, Illicit, Investigational
GefitinibThe metabolism of Gefitinib can be decreased when combined with Diphenhydramine.Approved, Investigational
GemfibrozilThe metabolism of Diphenhydramine can be decreased when combined with Gemfibrozil.Approved
GemifloxacinDiphenhydramine may increase the QTc-prolonging activities of Gemifloxacin.Approved, Investigational
GepefrineGepefrine may decrease the sedative activities of Diphenhydramine.Experimental
GepironeThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Gepirone.Investigational
GlutethimideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Glutethimide.Approved, Illicit
GoserelinDiphenhydramine may increase the QTc-prolonging activities of Goserelin.Approved
GranisetronDiphenhydramine may increase the QTc-prolonging activities of Granisetron.Approved, Investigational
GuanfacineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Guanfacine.Approved, Investigational
HalazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Halazepam.Approved, Illicit, Withdrawn
HalofantrineThe metabolism of Halofantrine can be decreased when combined with Diphenhydramine.Approved
HaloperidolDiphenhydramine may increase the QTc-prolonging activities of Haloperidol.Approved
HalothaneThe metabolism of Halothane can be decreased when combined with Diphenhydramine.Approved, Vet Approved
HeroinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Heroin.Approved, Illicit, Investigational
HexobarbitalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Hexobarbital.Approved
HyaluronidaseThe therapeutic efficacy of Hyaluronidase can be decreased when used in combination with Diphenhydramine.Approved, Investigational
HydrocodoneDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Hydrocodone.Approved, Illicit
HydromorphoneThe metabolism of Hydromorphone can be decreased when combined with Diphenhydramine.Approved, Illicit
HydroxyamphetamineHydroxyamphetamine may decrease the sedative activities of Diphenhydramine.Approved
HydroxyzineHydroxyzine may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved
IbrutinibThe metabolism of Ibrutinib can be decreased when combined with Diphenhydramine.Approved
IbutilideDiphenhydramine may increase the QTc-prolonging activities of Ibutilide.Approved
IdarubicinThe metabolism of Idarubicin can be decreased when combined with Diphenhydramine.Approved
IloperidoneDiphenhydramine may increase the QTc-prolonging activities of Iloperidone.Approved
ImatinibThe metabolism of Imatinib can be decreased when combined with Diphenhydramine.Approved
ImipramineThe metabolism of Imipramine can be decreased when combined with Diphenhydramine.Approved
IndalpineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Indalpine.Investigational, Withdrawn
IndinavirThe metabolism of Diphenhydramine can be decreased when combined with Indinavir.Approved
IndiplonThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Indiplon.Investigational
Iofetamine I-123Iofetamine I-123 may decrease the sedative activities of Diphenhydramine.Approved
Ipratropium bromideThe metabolism of Ipratropium bromide can be decreased when combined with Diphenhydramine.Approved
IrbesartanThe metabolism of Diphenhydramine can be decreased when combined with Irbesartan.Approved, Investigational
IsofluraneThe risk or severity of adverse effects can be increased when Isoflurane is combined with Diphenhydramine.Approved, Vet Approved
IsoniazidThe metabolism of Diphenhydramine can be decreased when combined with Isoniazid.Approved
IxazomibThe metabolism of Ixazomib can be decreased when combined with Diphenhydramine.Approved
KetamineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ketamine.Approved, Vet Approved
KetazolamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ketazolam.Approved
KetobemidoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ketobemidone.Approved, Investigational
KetoconazoleThe metabolism of Diphenhydramine can be decreased when combined with Ketoconazole.Approved, Investigational
LabetalolThe metabolism of Labetalol can be decreased when combined with Diphenhydramine.Approved
LamotrigineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lamotrigine.Approved, Investigational
LeflunomideThe metabolism of Diphenhydramine can be decreased when combined with Leflunomide.Approved, Investigational
LenvatinibDiphenhydramine may increase the QTc-prolonging activities of Lenvatinib.Approved
LeuprolideDiphenhydramine may increase the QTc-prolonging activities of Leuprolide.Approved, Investigational
LevetiracetamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levetiracetam.Approved, Investigational
LevobupivacaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levobupivacaine.Approved, Investigational
LevocabastineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levocabastine.Approved
LevocetirizineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levocetirizine.Approved
LevodopaThe metabolism of Levodopa can be decreased when combined with Diphenhydramine.Approved
LevofloxacinDiphenhydramine may increase the QTc-prolonging activities of Levofloxacin.Approved, Investigational
Levomethadyl AcetateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levomethadyl Acetate.Approved, Investigational
LevomilnacipranThe metabolism of Levomilnacipran can be decreased when combined with Diphenhydramine.Approved
LevorphanolThe risk or severity of adverse effects can be increased when Levorphanol is combined with Diphenhydramine.Approved
LidocaineThe metabolism of Diphenhydramine can be decreased when combined with Lidocaine.Approved, Vet Approved
LisdexamfetamineLisdexamfetamine may decrease the sedative activities of Diphenhydramine.Approved, Investigational
LisurideThe metabolism of Lisuride can be decreased when combined with Diphenhydramine.Approved, Investigational
LithiumThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lithium.Approved
LobeglitazoneThe metabolism of Diphenhydramine can be decreased when combined with Lobeglitazone.Approved, Investigational
LofentanilThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lofentanil.Illicit
LomustineThe metabolism of Lomustine can be decreased when combined with Diphenhydramine.Approved
LoperamideThe metabolism of Loperamide can be decreased when combined with Diphenhydramine.Approved
LopinavirDiphenhydramine may increase the QTc-prolonging activities of Lopinavir.Approved
LoprazolamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Loprazolam.Experimental
LoratadineThe metabolism of Loratadine can be decreased when combined with Diphenhydramine.Approved
LorazepamThe risk or severity of adverse effects can be increased when Lorazepam is combined with Diphenhydramine.Approved
LorcaserinThe metabolism of Lorcaserin can be decreased when combined with Diphenhydramine.Approved
LormetazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lormetazepam.Approved
LosartanThe metabolism of Diphenhydramine can be decreased when combined with Losartan.Approved
LovastatinThe metabolism of Diphenhydramine can be decreased when combined with Lovastatin.Approved, Investigational
LoxapineThe risk or severity of adverse effects can be increased when Loxapine is combined with Diphenhydramine.Approved
LuliconazoleThe serum concentration of Diphenhydramine can be increased when it is combined with Luliconazole.Approved
LumacaftorThe serum concentration of Diphenhydramine can be decreased when it is combined with Lumacaftor.Approved
LumefantrineDiphenhydramine may increase the QTc-prolonging activities of Lumefantrine.Approved
LurasidoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lurasidone.Approved
Magnesium SulfateMagnesium Sulfate may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved, Vet Approved
ManidipineThe metabolism of Diphenhydramine can be decreased when combined with Manidipine.Approved, Investigational
MaprotilineThe metabolism of Maprotiline can be decreased when combined with Diphenhydramine.Approved
MebicarThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Mebicar.Experimental
MeclizineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Meclizine.Approved
MedazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Medazepam.Experimental
MedetomidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Medetomidine.Vet Approved
MelatoninThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Melatonin.Approved, Nutraceutical, Vet Approved
MelperoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Melperone.Approved, Investigational
MephedroneMephedrone may decrease the sedative activities of Diphenhydramine.Investigational
MephentermineMephentermine may decrease the sedative activities of Diphenhydramine.Approved
MephenytoinThe metabolism of Mephenytoin can be decreased when combined with Diphenhydramine.Investigational, Withdrawn
MepivacaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Mepivacaine.Approved, Vet Approved
MeprobamateThe risk or severity of adverse effects can be increased when Meprobamate is combined with Diphenhydramine.Approved, Illicit
MeptazinolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Meptazinol.Experimental
MequitazineThe metabolism of Mequitazine can be decreased when combined with Diphenhydramine.Approved
MesoridazineThe metabolism of Mesoridazine can be decreased when combined with Diphenhydramine.Approved, Investigational
MetaxaloneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Metaxalone.Approved
MethadoneDiphenhydramine may increase the QTc-prolonging activities of Methadone.Approved
Methadyl AcetateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methadyl Acetate.Approved, Illicit
MethamphetamineThe metabolism of Methamphetamine can be decreased when combined with Diphenhydramine.Approved, Illicit
MethapyrileneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methapyrilene.Withdrawn
MethaqualoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methaqualone.Illicit, Withdrawn
MethocarbamolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methocarbamol.Approved, Vet Approved
MethohexitalThe risk or severity of adverse effects can be increased when Methohexital is combined with Diphenhydramine.Approved
MethotrimeprazineDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Methotrimeprazine.Approved
MethoxyfluraneThe metabolism of Methoxyflurane can be decreased when combined with Diphenhydramine.Approved, Investigational, Vet Approved
MethoxyphenamineMethoxyphenamine may decrease the sedative activities of Diphenhydramine.Experimental
MethsuximideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methsuximide.Approved
MethylecgonineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methylecgonine.Experimental
MethylphenidateThe metabolism of Methylphenidate can be decreased when combined with Diphenhydramine.Approved, Investigational
MethylphenobarbitalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methylphenobarbital.Approved
MethyprylonThe metabolism of Methyprylon can be decreased when combined with Diphenhydramine.Approved, Illicit, Withdrawn
MetoclopramideThe metabolism of Metoclopramide can be decreased when combined with Diphenhydramine.Approved, Investigational
MetoprololThe serum concentration of Metoprolol can be increased when it is combined with Diphenhydramine.Approved, Investigational
MetyrosineDiphenhydramine may increase the sedative activities of Metyrosine.Approved
MexiletineThe metabolism of Diphenhydramine can be decreased when combined with Mexiletine.Approved
MianserinThe metabolism of Mianserin can be decreased when combined with Diphenhydramine.Approved, Investigational
MidazolamThe risk or severity of adverse effects can be increased when Midazolam is combined with Diphenhydramine.Approved, Illicit
Midomafetamine3,4-Methylenedioxymethamphetamine may decrease the sedative activities of Diphenhydramine.Experimental, Illicit, Investigational
MidostaurinThe metabolism of Diphenhydramine can be decreased when combined with Midostaurin.Approved
MifepristoneThe serum concentration of Diphenhydramine can be increased when it is combined with Mifepristone.Approved, Investigational
MilnacipranThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Milnacipran.Approved
MinaprineThe metabolism of Minaprine can be decreased when combined with Diphenhydramine.Approved
MinocyclineMinocycline may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved, Investigational
MirabegronThe metabolism of Mirabegron can be decreased when combined with Diphenhydramine.Approved
MirtazapineDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Mirtazapine.Approved
MMDAMMDA may decrease the sedative activities of Diphenhydramine.Experimental, Illicit
MoclobemideThe metabolism of Moclobemide can be decreased when combined with Diphenhydramine.Approved
ModafinilThe metabolism of Diphenhydramine can be decreased when combined with Modafinil.Approved, Investigational
MolindoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Molindone.Approved
MorphineThe metabolism of Morphine can be decreased when combined with Diphenhydramine.Approved, Investigational
MoxifloxacinDiphenhydramine may increase the QTc-prolonging activities of Moxifloxacin.Approved, Investigational
NabiloneNabilone may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved, Investigational
NalbuphineThe risk or severity of adverse effects can be increased when Nalbuphine is combined with Diphenhydramine.Approved
NateglinideThe metabolism of Nateglinide can be decreased when combined with Diphenhydramine.Approved, Investigational
NebivololThe serum concentration of Nebivolol can be increased when it is combined with Diphenhydramine.Approved, Investigational
NefazodoneThe metabolism of Nefazodone can be decreased when combined with Diphenhydramine.Approved, Withdrawn
NelfinavirThe metabolism of Diphenhydramine can be decreased when combined with Nelfinavir.Approved
NetupitantThe metabolism of Netupitant can be decreased when combined with Diphenhydramine.Approved
NevirapineThe metabolism of Diphenhydramine can be increased when combined with Nevirapine.Approved
NicardipineThe metabolism of Diphenhydramine can be decreased when combined with Nicardipine.Approved
NicergolineThe metabolism of Nicergoline can be decreased when combined with Diphenhydramine.Approved, Investigational
NicotineThe metabolism of Nicotine can be decreased when combined with Diphenhydramine.Approved
NifedipineThe metabolism of Nifedipine can be decreased when combined with Diphenhydramine.Approved
NilotinibDiphenhydramine may increase the QTc-prolonging activities of Nilotinib.Approved, Investigational
NitrazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Nitrazepam.Approved
NitrofuralThe metabolism of Nitrofural can be decreased when combined with Diphenhydramine.Approved, Investigational, Vet Approved
Nitrous oxideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Nitrous oxide.Approved, Vet Approved
NorfluraneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Norflurane.Investigational
NormethadoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Normethadone.Approved, Illicit
NortriptylineThe metabolism of Nortriptyline can be decreased when combined with Diphenhydramine.Approved
OfloxacinDiphenhydramine may increase the QTc-prolonging activities of Ofloxacin.Approved
OlanzapineThe metabolism of Olanzapine can be decreased when combined with Diphenhydramine.Approved, Investigational
OlopatadineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Olopatadine.Approved
OmeprazoleThe metabolism of Diphenhydramine can be decreased when combined with Omeprazole.Approved, Investigational, Vet Approved
OndansetronDiphenhydramine may increase the QTc-prolonging activities of Ondansetron.Approved
OpiumThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Opium.Approved, Illicit
OrphenadrineDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Orphenadrine.Approved
OsanetantThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Osanetant.Investigational
OsimertinibThe serum concentration of Diphenhydramine can be decreased when it is combined with Osimertinib.Approved
OxazepamThe risk or severity of adverse effects can be increased when Oxazepam is combined with Diphenhydramine.Approved
OxethazaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Oxethazaine.Approved, Investigational
OxprenololThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Oxprenolol.Approved
OxybuprocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Oxybuprocaine.Approved
OxycodoneThe metabolism of Oxycodone can be decreased when combined with Diphenhydramine.Approved, Illicit, Investigational
OxymorphoneThe metabolism of Oxymorphone can be decreased when combined with Diphenhydramine.Approved, Investigational, Vet Approved
PaliperidoneDiphenhydramine may increase the QTc-prolonging activities of Paliperidone.Approved
PalonosetronThe metabolism of Palonosetron can be decreased when combined with Diphenhydramine.Approved, Investigational
PanobinostatThe serum concentration of Diphenhydramine can be increased when it is combined with Panobinostat.Approved, Investigational
PantoprazoleThe metabolism of Diphenhydramine can be decreased when combined with Pantoprazole.Approved
ParaldehydeDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Paraldehyde.Approved, Investigational
ParoxetineThe metabolism of Diphenhydramine can be decreased when combined with Paroxetine.Approved, Investigational
PazopanibDiphenhydramine may increase the QTc-prolonging activities of Pazopanib.Approved
Peginterferon alfa-2bThe serum concentration of Diphenhydramine can be decreased when it is combined with Peginterferon alfa-2b.Approved
PenfluridolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Penfluridol.Experimental
PentamidineDiphenhydramine may increase the QTc-prolonging activities of Pentamidine.Approved
PentazocineThe risk or severity of adverse effects can be increased when Pentazocine is combined with Diphenhydramine.Approved, Vet Approved
PentobarbitalThe risk or severity of adverse effects can be increased when Pentobarbital is combined with Diphenhydramine.Approved, Vet Approved
PerampanelPerampanel may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved
PerazineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Perazine.Investigational
PerflutrenDiphenhydramine may increase the QTc-prolonging activities of Perflutren.Approved
PerhexilineThe metabolism of Perhexiline can be decreased when combined with Diphenhydramine.Approved, Investigational
PerospironeThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Perospirone.Approved
PerphenazineThe metabolism of Perphenazine can be decreased when combined with Diphenhydramine.Approved
PethidineThe metabolism of Pethidine can be decreased when combined with Diphenhydramine.Approved
PhenacetinThe metabolism of Phenacetin can be decreased when combined with Diphenhydramine.Withdrawn
PhenazocineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Phenazocine.Experimental
PhenforminThe metabolism of Phenformin can be decreased when combined with Diphenhydramine.Approved, Investigational, Withdrawn
PhenibutThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Phenibut.Experimental
PhenobarbitalThe metabolism of Diphenhydramine can be increased when combined with Phenobarbital.Approved
PhenoperidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Phenoperidine.Experimental
PhenoxyethanolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Phenoxyethanol.Approved
PhenterminePhentermine may decrease the sedative activities of Diphenhydramine.Approved, Illicit
PhenytoinThe metabolism of Diphenhydramine can be increased when combined with Phenytoin.Approved, Vet Approved
PimozideDiphenhydramine may increase the QTc-prolonging activities of Pimozide.Approved
PindololThe metabolism of Pindolol can be decreased when combined with Diphenhydramine.Approved
PipamperoneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Pipamperone.Approved, Investigational
PiperazineThe metabolism of Piperazine can be decreased when combined with Diphenhydramine.Approved, Vet Approved
PipotiazineThe metabolism of Pipotiazine can be decreased when combined with Diphenhydramine.Approved, Investigational
PiritramideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Piritramide.Investigational
PizotifenThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Pizotifen.Approved
PomalidomideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Pomalidomide.Approved
PonatinibThe metabolism of Ponatinib can be decreased when combined with Diphenhydramine.Approved
PramipexoleDiphenhydramine may increase the sedative activities of Pramipexole.Approved, Investigational
PramocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Pramocaine.Approved
PrazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Prazepam.Approved, Illicit
PregabalinThe risk or severity of adverse effects can be increased when Pregabalin is combined with Diphenhydramine.Approved, Illicit, Investigational
PrilocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Prilocaine.Approved
PrimaquineDiphenhydramine may increase the QTc-prolonging activities of Primaquine.Approved
PrimidoneThe metabolism of Diphenhydramine can be increased when combined with Primidone.Approved, Vet Approved
ProcainamideDiphenhydramine may increase the QTc-prolonging activities of Procainamide.Approved
ProcaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Procaine.Approved, Investigational, Vet Approved
ProchlorperazineThe metabolism of Prochlorperazine can be decreased when combined with Diphenhydramine.Approved, Vet Approved
ProgesteroneThe metabolism of Progesterone can be decreased when combined with Diphenhydramine.Approved, Vet Approved
PromazineDiphenhydramine may increase the QTc-prolonging activities of Promazine.Approved, Vet Approved
PromethazineThe metabolism of Promethazine can be decreased when combined with Diphenhydramine.Approved
PropafenoneThe serum concentration of Diphenhydramine can be increased when it is combined with Propafenone.Approved
PropanididThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Propanidid.Experimental
ProparacaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Proparacaine.Approved, Vet Approved
PropofolThe metabolism of Propofol can be decreased when combined with Diphenhydramine.Approved, Investigational, Vet Approved
PropoxycaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Propoxycaine.Approved
PropranololThe metabolism of Propranolol can be decreased when combined with Diphenhydramine.Approved, Investigational
ProtriptylineThe metabolism of Protriptyline can be decreased when combined with Diphenhydramine.Approved
ProxibarbalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Proxibarbal.Experimental
PSD502The risk or severity of adverse effects can be increased when Diphenhydramine is combined with PSD502.Investigational
PseudoephedrineThe metabolism of Pseudoephedrine can be decreased when combined with Diphenhydramine.Approved
PyrimethamineThe metabolism of Diphenhydramine can be decreased when combined with Pyrimethamine.Approved, Vet Approved
QuazepamThe serum concentration of Diphenhydramine can be increased when it is combined with Quazepam.Approved, Illicit
QuetiapineDiphenhydramine may increase the QTc-prolonging activities of Quetiapine.Approved
QuinidineDiphenhydramine may increase the QTc-prolonging activities of Quinidine.Approved
QuinineDiphenhydramine may increase the QTc-prolonging activities of Quinine.Approved
QuinisocaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Quinisocaine.Experimental
RacloprideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Raclopride.Investigational
RamelteonThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ramelteon.Approved, Investigational
RanitidineThe metabolism of Ranitidine can be decreased when combined with Diphenhydramine.Approved
RanolazineThe metabolism of Diphenhydramine can be decreased when combined with Ranolazine.Approved, Investigational
RemifentanilThe risk or severity of adverse effects can be increased when Remifentanil is combined with Diphenhydramine.Approved
RemoxiprideThe metabolism of Remoxipride can be decreased when combined with Diphenhydramine.Approved, Withdrawn
repinotanThe metabolism of repinotan can be decreased when combined with Diphenhydramine.Investigational
ReserpineThe risk or severity of adverse effects can be increased when Reserpine is combined with Diphenhydramine.Approved, Investigational
RifampicinThe metabolism of Diphenhydramine can be increased when combined with Rifampicin.Approved
RifapentineThe metabolism of Diphenhydramine can be increased when combined with Rifapentine.Approved
RisperidoneThe metabolism of Risperidone can be decreased when combined with Diphenhydramine.Approved, Investigational
RitanserinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ritanserin.Investigational
RitobegronRitobegron may decrease the sedative activities of Diphenhydramine.Investigational
RitonavirThe metabolism of Diphenhydramine can be decreased when combined with Ritonavir.Approved, Investigational
RolapitantThe metabolism of Diphenhydramine can be decreased when combined with Rolapitant.Approved
RomifidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Romifidine.Vet Approved
RopiniroleDiphenhydramine may increase the sedative activities of Ropinirole.Approved, Investigational
RopivacaineThe metabolism of Ropivacaine can be decreased when combined with Diphenhydramine.Approved
RotigotineDiphenhydramine may increase the sedative activities of Rotigotine.Approved
RucaparibThe metabolism of Rucaparib can be decreased when combined with Diphenhydramine.Approved, Investigational
RufinamideThe risk or severity of adverse effects can be increased when Rufinamide is combined with Diphenhydramine.Approved
RupatadineThe metabolism of Rupatadine can be decreased when combined with Diphenhydramine.Approved
SaquinavirDiphenhydramine may increase the QTc-prolonging activities of Saquinavir.Approved, Investigational
ScopolamineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Scopolamine.Approved
SecobarbitalThe metabolism of Diphenhydramine can be increased when combined with Secobarbital.Approved, Vet Approved
SepranoloneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Sepranolone.Investigational
SertindoleThe metabolism of Sertindole can be decreased when combined with Diphenhydramine.Approved, Investigational, Withdrawn
SertralineThe metabolism of Sertraline can be decreased when combined with Diphenhydramine.Approved
SevofluraneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Sevoflurane.Approved, Vet Approved
SildenafilThe metabolism of Sildenafil can be decreased when combined with Diphenhydramine.Approved, Investigational
SimeprevirThe metabolism of Diphenhydramine can be decreased when combined with Simeprevir.Approved
SimvastatinThe metabolism of Simvastatin can be decreased when combined with Diphenhydramine.Approved
Sodium oxybateSodium oxybate may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved
SorafenibThe metabolism of Diphenhydramine can be decreased when combined with Sorafenib.Approved, Investigational
SotalolDiphenhydramine may increase the QTc-prolonging activities of Sotalol.Approved
SparteineThe metabolism of Sparteine can be decreased when combined with Diphenhydramine.Experimental
StiripentolThe metabolism of Diphenhydramine can be decreased when combined with Stiripentol.Approved
SufentanilThe risk or severity of adverse effects can be increased when Sufentanil is combined with Diphenhydramine.Approved, Investigational
SulfadiazineThe metabolism of Diphenhydramine can be decreased when combined with Sulfadiazine.Approved, Vet Approved
SulfamethoxazoleThe metabolism of Diphenhydramine can be decreased when combined with Sulfamethoxazole.Approved
SulfisoxazoleThe metabolism of Diphenhydramine can be decreased when combined with Sulfisoxazole.Approved, Vet Approved
SulpirideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Sulpiride.Approved, Investigational
SultoprideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Sultopride.Experimental
SuvorexantDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Suvorexant.Approved
TamoxifenThe serum concentration of the active metabolites of Tamoxifen can be reduced when Tamoxifen is used in combination with Diphenhydramine resulting in a loss in efficacy.Approved
TamsulosinThe metabolism of Tamsulosin can be decreased when combined with Diphenhydramine.Approved, Investigational
TandospironeThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tandospirone.Investigational
TapentadolTapentadol may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.Approved
TasimelteonThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tasimelteon.Approved
Technetium Tc-99m tilmanoceptDiphenhydramine may decrease effectiveness of Technetium Tc-99m tilmanocept as a diagnostic agent.Approved, Investigational
TegaserodThe metabolism of Tegaserod can be decreased when combined with Diphenhydramine.Investigational, Withdrawn
TelavancinDiphenhydramine may increase the QTc-prolonging activities of Telavancin.Approved
TelithromycinDiphenhydramine may increase the QTc-prolonging activities of Telithromycin.Approved
TemazepamThe risk or severity of adverse effects can be increased when Temazepam is combined with Diphenhydramine.Approved
Tenofovir disoproxilThe metabolism of Diphenhydramine can be decreased when combined with Tenofovir disoproxil.Approved, Investigational
TerbinafineThe metabolism of Diphenhydramine can be decreased when combined with Terbinafine.Approved, Investigational, Vet Approved
TerfenadineThe metabolism of Terfenadine can be decreased when combined with Diphenhydramine.Withdrawn
TeriflunomideThe serum concentration of Diphenhydramine can be decreased when it is combined with Teriflunomide.Approved
TesmilifeneThe metabolism of Tesmilifene can be decreased when combined with Diphenhydramine.Investigational
TetrabenazineDiphenhydramine may increase the QTc-prolonging activities of Tetrabenazine.Approved
TetracaineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tetracaine.Approved, Vet Approved
TetrahydropalmatineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tetrahydropalmatine.Investigational
TetrodotoxinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tetrodotoxin.Investigational
ThalidomideDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Thalidomide.Approved, Investigational, Withdrawn
TheophyllineThe metabolism of Diphenhydramine can be decreased when combined with Theophylline.Approved
ThiamylalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Thiamylal.Approved, Vet Approved
ThiopentalThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Thiopental.Approved, Vet Approved
ThioridazineThe serum concentration of Thioridazine can be increased when it is combined with Diphenhydramine.Approved, Withdrawn
ThiotepaThe metabolism of Diphenhydramine can be decreased when combined with Thiotepa.Approved
ThiothixeneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Thiothixene.Approved
TiagabineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tiagabine.Approved
TiaprideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tiapride.Approved, Investigational
TicagrelorThe metabolism of Diphenhydramine can be decreased when combined with Ticagrelor.Approved
TiclopidineThe metabolism of Diphenhydramine can be decreased when combined with Ticlopidine.Approved
TiletamineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tiletamine.Vet Approved
TilidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tilidine.Experimental
TimololThe metabolism of Timolol can be decreased when combined with Diphenhydramine.Approved
TiotropiumThe metabolism of Tiotropium can be decreased when combined with Diphenhydramine.Approved
TipranavirThe metabolism of Diphenhydramine can be decreased when combined with Tipranavir.Approved, Investigational
TizanidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tizanidine.Approved
TolbutamideThe metabolism of Diphenhydramine can be decreased when combined with Tolbutamide.Approved
TolcaponeThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tolcapone.Approved, Withdrawn
TolterodineThe metabolism of Tolterodine can be decreased when combined with Diphenhydramine.Approved, Investigational
TopiramateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Topiramate.Approved
TopiroxostatThe metabolism of Diphenhydramine can be decreased when combined with Topiroxostat.Approved, Investigational
ToremifeneDiphenhydramine may increase the QTc-prolonging activities of Toremifene.Approved, Investigational
TrabectedinThe metabolism of Trabectedin can be decreased when combined with Diphenhydramine.Approved, Investigational
TramadolThe therapeutic efficacy of Tramadol can be decreased when used in combination with Diphenhydramine.Approved, Investigational
Trans-2-PhenylcyclopropylamineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Trans-2-Phenylcyclopropylamine.Experimental
TranylcypromineThe metabolism of Diphenhydramine can be decreased when combined with Tranylcypromine.Approved
TrazodoneThe metabolism of Trazodone can be decreased when combined with Diphenhydramine.Approved, Investigational
TriazolamThe risk or severity of adverse effects can be increased when Triazolam is combined with Diphenhydramine.Approved
Tricaine methanesulfonateThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tricaine methanesulfonate.Vet Approved
TrichloroethyleneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Trichloroethylene.Experimental
TrifluoperazineThe risk or severity of adverse effects can be increased when Trifluoperazine is combined with Diphenhydramine.Approved
TrifluperidolThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Trifluperidol.Experimental
TriflupromazineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Triflupromazine.Approved, Vet Approved
TrimethoprimThe metabolism of Diphenhydramine can be decreased when combined with Trimethoprim.Approved, Vet Approved
TrimipramineThe metabolism of Trimipramine can be decreased when combined with Diphenhydramine.Approved
TriprolidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Triprolidine.Approved
UmeclidiniumThe metabolism of Umeclidinium can be decreased when combined with Diphenhydramine.Approved
ValbenazineThe metabolism of Valbenazine can be decreased when combined with Diphenhydramine.Approved, Investigational
Valproic AcidThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Valproic Acid.Approved, Investigational
ValsartanThe metabolism of Diphenhydramine can be decreased when combined with Valsartan.Approved, Investigational
VandetanibDiphenhydramine may increase the QTc-prolonging activities of Vandetanib.Approved
VemurafenibThe serum concentration of Diphenhydramine can be increased when it is combined with Vemurafenib.Approved
VenlafaxineThe metabolism of Diphenhydramine can be decreased when combined with Venlafaxine.Approved
VeraliprideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Veralipride.Experimental
VernakalantThe metabolism of Vernakalant can be decreased when combined with Diphenhydramine.Approved, Investigational
VigabatrinThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Vigabatrin.Approved
VilazodoneThe metabolism of Vilazodone can be decreased when combined with Diphenhydramine.Approved
VinblastineThe metabolism of Vinblastine can be decreased when combined with Diphenhydramine.Approved
VinorelbineThe metabolism of Vinorelbine can be decreased when combined with Diphenhydramine.Approved, Investigational
Vinyl etherThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Vinyl ether.Experimental
VoriconazoleThe metabolism of Diphenhydramine can be decreased when combined with Voriconazole.Approved, Investigational
VortioxetineThe metabolism of Vortioxetine can be decreased when combined with Diphenhydramine.Approved
XenonThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Xenon.Experimental
XylazineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Xylazine.Vet Approved
YohimbineThe metabolism of Yohimbine can be decreased when combined with Diphenhydramine.Approved, Vet Approved
ZafirlukastThe metabolism of Diphenhydramine can be decreased when combined with Zafirlukast.Approved, Investigational
ZalcitabineThe metabolism of Zalcitabine can be decreased when combined with Diphenhydramine.Approved, Investigational
ZaleplonThe risk or severity of adverse effects can be increased when Zaleplon is combined with Diphenhydramine.Approved, Illicit, Investigational
ZiconotideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Ziconotide.Approved
ZimelidineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Zimelidine.Withdrawn
ZiprasidoneDiphenhydramine may increase the QTc-prolonging activities of Ziprasidone.Approved
ZolazepamThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Zolazepam.Vet Approved
ZolpidemDiphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Zolpidem.Approved
ZonisamideThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Zonisamide.Approved, Investigational
ZopicloneThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Zopiclone.Approved
ZotepineThe risk or severity of adverse effects can be increased when Diphenhydramine is combined with Zotepine.Approved, Investigational
ZucapsaicinThe metabolism of Diphenhydramine can be decreased when combined with Zucapsaicin.Approved
ZuclopenthixolDiphenhydramine may increase the QTc-prolonging activities of Zuclopenthixol.Approved, Investigational
Food Interactions
  • Avoid alcohol.
  • Take with food.

References

Synthesis Reference

Alison B. Lukacsko, Joseph J. Piala, "Effect of a combination of a terbutaline, diphenhydramine and ranitidine composition on gastrointestinal injury produced by nonsteroidal anti-inflammatory compositions." U.S. Patent US5260333, issued December, 1983.

US5260333
General References
  1. Raphael GD, Angello JT, Wu MM, Druce HM: Efficacy of diphenhydramine vs desloratadine and placebo in patients with moderate-to-severe seasonal allergic rhinitis. Ann Allergy Asthma Immunol. 2006 Apr;96(4):606-14. [PubMed:16680933]
  2. Abdi A, Rose E, Levine M: Diphenhydramine overdose with intraventricular conduction delay treated with hypertonic sodium bicarbonate and i.v. lipid emulsion. West J Emerg Med. 2014 Nov;15(7):855-8. doi: 10.5811/westjem.2014.8.23407. Epub 2014 Sep 19. [PubMed:25493135]
External Links
Human Metabolome Database
HMDB01927
KEGG Drug
D00300
KEGG Compound
C06960
PubChem Compound
3100
PubChem Substance
46505484
ChemSpider
2989
BindingDB
50017674
ChEBI
4636
ChEMBL
CHEMBL657
Therapeutic Targets Database
DAP000490
PharmGKB
PA449349
IUPHAR
1224
Guide to Pharmacology
GtP Drug Page
HET
2PM
RxList
RxList Drug Page
Drugs.com
Drugs.com Drug Page
Wikipedia
Diphenhydramine
ATC Codes
D04AA32 — DiphenhydramineD04AA33 — Diphenhydramine methylbromideR06AA52 — Diphenhydramine, combinationsR06AA02 — Diphenhydramine
AHFS Codes
  • 04:04.04 — Ethanolamine Derivatives
  • 04:04.00 — First Generation Antihistamines
PDB Entries
2aot
MSDS
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Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
0Not Yet RecruitingTreatmentPost-Traumatic Headaches1
1CompletedNot AvailableAutonomic Failure / Idiopathic orthostatic hypotension1
1CompletedNot AvailableHealthy Volunteers2
1CompletedNot AvailableTherapeutic Equivalence1
1CompletedBasic ScienceAllergic Rhinitis (AR)1
1CompletedBasic ScienceNasal Stuffiness1
1CompletedTreatmentHealthy Volunteers3
1CompletedTreatmentMajor Depressive Disorder (MDD)1
1CompletedTreatmentRestless Legs Syndrome (RLS)1
1RecruitingDiagnosticPatients With Suspected Malignancies of the Pituitary Gland1
1RecruitingDiagnosticA Diagnosis of Any Resectable Lung or Pleural Nodule1
1RecruitingScreeningFibrosis1
1RecruitingTreatmentDiseases of Oesophagus Stomach and Duodenum1
1RecruitingTreatmentGraft Versus Host Disease (GVHD) / Sickle Cell Disorders1
1RecruitingTreatmentMultiple Myeloma (MM)1
1RecruitingTreatmentNeoplasms Malignant1
1RecruitingTreatmentPompe's Disease1
1RecruitingTreatmentTransplantation, Liver1
1RecruitingTreatmentTumors, Solid1
1TerminatedNot AvailableHealthy Male Volunteers1
1TerminatedBasic ScienceDrug Metabolism, Poor, CYP2D6-RELATED1
1WithdrawnDiagnosticAbdominal Pain (AP) / Gallbladder disorders / Gallstone formation / Jaundice / Pancreatitis1
1, 2CompletedTreatmentKidney Diseases / Transplantation, Kidney1
1, 2CompletedTreatmentLeukemia, Acute Lymphocytic (ALL) / Leukemia, Acute Myelogenous (AML) / Leukemia, Chronic Myelogenous (CML) / Myelodysplastic Syndromes (MDS) / Non-Hodgkin's Lymphoma (NHL)1
1, 2RecruitingTreatmentAdult Living Donor Kidney Transplant Recipients / Living Kidney Donors / Transplant, Kidney1
1, 2RecruitingTreatmentLiver Transplant Recipients / Living Donor (of the Respective Liver Transplant Recipient)1
1, 2RecruitingTreatmentLung Cancers1
2Active Not RecruitingTreatmentAdvanced Stage Diffuse Large B-Cell Non-Hodgkin's Lymphoma / Non-Hodgkin's Lymphoma (NHL)1
2Active Not RecruitingTreatmentMultiple Myeloma (MM)1
2Active Not RecruitingTreatmentNephritis, Lupus1
2Active Not RecruitingTreatmentRenal Cancers1
2CompletedNot AvailableCancers / Tumors, Solid1
2CompletedSupportive CareStomatitis, Aphthous1
2CompletedTreatmentAcute Cerebrovascular Accidents / Edema of the cerebrum1
2CompletedTreatmentBlood Cancers / CLL / Graft Versus Host Disease (GVHD) / Hodgkins Disease (HD) / Leukemias / Malignancies / NHL / Smith-Magenis Syndrome1
2CompletedTreatmentBlood and Marrow Transplant (BMT) / Multiple Myeloma (MM) / Transplantation, Autologous / Transplantation, Homologous1
2CompletedTreatmentCancer, Breast1
2CompletedTreatmentChronic Idiopathic Urticaria1
2CompletedTreatmentDepressive State1
2CompletedTreatmentEndometrial Cancers1
2CompletedTreatmentLupus Erythematosus, Systemic1
2CompletedTreatmentMalignant Lymphomas1
2CompletedTreatmentRejection, Transplant1
2CompletedTreatmentRenal Cell Adenocarcinoma1
2CompletedTreatmentRestless Legs Syndrome (RLS)1
2CompletedTreatmentVulvodynia1
2RecruitingTreatmentAlcohol Dependence1
2RecruitingTreatmentCocaine-Related Disorders1
2RecruitingTreatmentPlasma Cell Myeloma2
2RecruitingTreatmentT-cell Type Acute Leukemia-Precursor T-lymphoblastic Lymphoma/Leukaemia1
2RecruitingTreatmentTransplant, Kidney1
2TerminatedSupportive CareNausea / Unspecified Childhood Solid Tumor, Protocol Specific / Vomiting1
2TerminatedTreatmentChronic Hepatitis B Infection1
2TerminatedTreatmentProstate Cancer1
2TerminatedTreatmentTransplantation, Kidney1
2, 3CompletedTreatmentLupus Erythematosus, Systemic1
2, 3CompletedTreatmentVesicular Stomatitis1
2, 3RecruitingTreatmentMalaria caused by Plasmodium falciparum1
2, 3TerminatedTreatmentLupus Erythematosus, Systemic1
3CompletedTreatmentAcute Urticaria1
3CompletedTreatmentChronic Idiopathic Urticaria1
3CompletedTreatmentElective Caesarean Section Surgeries1
3CompletedTreatmentHealthy Volunteers1
3CompletedTreatmentMigraines1
3CompletedTreatmentNephritis, Lupus1
3Not Yet RecruitingTreatmentAcute Urticaria1
3RecruitingTreatmentHeadaches / Intranasal Ketamine1
3RecruitingTreatmentPost-Traumatic Headaches1
3TerminatedTreatmentAnxiety Disorders / Dementias / Depressive State / Psychosomatic Disorders / Schizophrenic Disorders1
3Unknown StatusTreatmentSleeplessness1
3WithdrawnTreatmentCoughing / Inflammatory Reaction / Rhinitis1
4Active Not RecruitingSupportive CareAdjunct Anesthesia Medication / Colonoscopy1
4CompletedDiagnosticAsthma Bronchial1
4CompletedPreventionHypnotic / Specified Sedative1
4CompletedTreatmentCough Reflex Sensitivity1
4CompletedTreatmentHeadaches1
4CompletedTreatmentInfections, Bacterial1
4CompletedTreatmentMigraines2
4CompletedTreatmentMigrainous Headache / Nausea / Restlessness1
4CompletedTreatmentNasal Stuffiness1
4CompletedTreatmentExtra-pyramidal symptoms / Nausea1
4CompletedTreatmentNeurogenic Intermittent Claudication / Spinal Stenosis of Lumbar Region1
4CompletedTreatmentOccasional Sleeplessness1
4RecruitingTreatmentMigraines1
4SuspendedTreatmentMigrainous Headache1
Not AvailableActive Not RecruitingScreeningAlcoholism1
Not AvailableCompletedNot AvailablePain, Neuropathic1
Not AvailableCompletedBasic ScienceHyperalgesia1
Not AvailableCompletedBasic ScienceMemory, Long-Term / Memory, Short-Term1
Not AvailableCompletedPreventionGeneral Surgery / Pain1
Not AvailableCompletedPreventionHeadaches1
Not AvailableCompletedSupportive CareFocus of Study: Absorption of the Three Components in the Topical ABH Gel in Healthy Volunteers, and Determine if There Are Any Adverse Effects / Healthy Volunteers1
Not AvailableCompletedSupportive CareNausea / Vomiting1
Not AvailableCompletedTreatmentBenign Paroxysmal Positional Vertigo (BPPV)1
Not AvailableCompletedTreatmentEndometriosis1
Not AvailableCompletedTreatmentEndoscopy / Sedation therapy1
Not AvailableCompletedTreatmentItching1
Not AvailableCompletedTreatmentPain1
Not AvailableEnrolling by InvitationTreatmentMigrainous Headache1
Not AvailableRecruitingTreatmentAlcohol-Related Disorders / Brain Injury / Chronic Diseases / Depressive State / Mild Cognitive Impairment (MCI) / Pain / Posttraumatic Stress Disorders / Quality of Life / Substance-Related Disorders / Suicidal Ideation / Wounds and Injuries1
Not AvailableRecruitingTreatmentAnxiety Disorders / Moods Disorders / Pain Disorders / Somatization Disorder1
Not AvailableSuspendedDiagnosticBulimia Nervosa (BN) / Catechol-O-methyltransferase / Dopamine / Eating Disorders / Reward1
Not AvailableTerminatedTreatmentHuman Immunodeficiency Virus (HIV) Infections1
Not AvailableTerminatedTreatmentPrimary Headaches (Includes Migraines, Tension, Cluster Headaches)1
Not AvailableUnknown StatusSupportive CareEndoscopic Retrograde Cholangiopancreatography (ERCP) / Endoscopic Ultrasound (EUS)1
Not AvailableUnknown StatusTreatmentPost Operative Nausea and Vomiting (PONV) / Rescue Emetic Therapy1

Pharmacoeconomics

Manufacturers
Not Available
Packagers
Dosage forms
FormRouteStrength
Capsule; kitOral
CreamTopical20 mg/mL
CreamTopical2 mL/100mL
PowderOral25 mg/1
LiquidOral12.5 mg
Tablet, chewableOral12.5 mg/1
Tablet, film coatedOral25 mg/1
SolutionOral12.5 mg
GelTopical2 g/100g
CreamTopical2.0 %
PatchTopical
Kit
TabletOral25 mg
Tablet, coatedOral25 mg/1
Tablet, chewableOral12.5 mg
LiquidTopical
LiquidOral6.25 mg
CreamTopical2 %
ElixirOral12.5 mg
GelTopical20 mg/mL
Tablet, chewableOral25 mg
GelTopical2 %
TabletOral25 mg/250mg
StripOral25 mg
LotionTopical
TabletOral19 mg
StripOral19 mg
SuspensionOral
TabletOral12.5 mg/1
LiquidOral12.5 mg/5mL
OintmentTopical
KitTopical
KitOral
TabletOral38.0 mg
Capsule, coatedOral25 mg/1
Injection, solutionIntravenous50 mg/mL
Capsule, liquid filledOral20 mg/1
Capsule, gelatin coatedOral25 mg/1
SyrupOral6.25 mg
LiquidIntravenous50 mg
ElixirOral12.5 mg/5mL
ElixirOral25 mg/10mL
InjectionIntramuscular50 mg/mL
InjectionIntramuscular; Intravenous50 mg/mL
Injection, solutionIntramuscular; Intravenous50 mg/mL
SolutionOral25 mg/10mL
SolutionOral50 mg/20mL
LiquidIntramuscular; Intravenous50 mg
KitOral; Topical
TabletOral
Tablet, film coatedOral
LiquidOral50 mg/30mL
SolutionOral50 mg/40mL
KitOral
Aerosol, sprayTopical
Capsule, coatedOral
Tablet, coatedOral
PowderOral
Capsule, liquid filledOral
LiquidTopical20.3 g/L
SprayTopical2 g/100mL
AerosolTopical
SolutionTopical
GelTopical2 g/100mL
StripOral12.5 mg
TabletOral12.5 mg
Tablet, orally disintegratingOral12.5 mg/1
LinimentTopical
CreamTopical
Kit
LozengeOral25 mg
StripOral
TabletOral50 mg/1
CapsuleOral25 mg
SolutionOral50 mg
CapsuleOral50 mg/1
Tablet, film coatedOral50 mg/1
Capsule, liquid filledOral50 mg/21
SolutionOral
TabletOral50 mg
CapsuleOral
Capsule, gelatin coatedOral
ElixirOral2.5 mg
SyrupOral12.5 mg/5mL
GelTopical20.5 mg/mL
SprayTopical
LiquidOral
PlasterTopical
SolutionIntramuscular; Intravenous50 mg
GelTopical.2 g/10mL
Capsule, liquid filledOral50 mg/1
Capsule, liquid filledOral25 mg/1
TabletOral25 mg/1
Tablet, coatedOral50 mg/1
GelTopical
GelTopical20 mg/g
SprayTopical20 mg/mL
Powder, for solutionOral
SyrupOral
CapsuleOral25 mg/1
SolutionOral50 mg/30mL
Kit; tabletOral
CapsuleOral50 mg
Tablet, chewableOral25 mg/1
LiquidOral6.25 mg/mL
SolutionOral12.5 mg/5mL
LiquidOral25 mg/10mL
Capsule, gelatin coatedOral50 mg/21
Granule, for solutionOral
SprayTopical2.0 %
LiquidOral50 mg
Prices
Unit descriptionCostUnit
DiphenhydrAMINE HCl 100 50 mg capsule Bottle13.99USD bottle
Diphenhydramine 50 mg/ml3.94USD ml
Diphenhydramine 50 mg/ml vial1.69USD ml
DiphenhydrAMINE HCl 50 mg/ml vial1.44USD vial
Dytan 25 mg tablet chewable1.37USD tablet
Benadryl 50 mg/ml vial1.36USD ml
Diphenmax 25 mg tablet1.24USD tablet
Benadryl allergy 25 mg strips0.45USD strip
Unisom sleep aid tablet0.34USD tablet
Sleep-eze 3 tablet0.29USD tablet
Compoz 50 mg tablet0.27USD tablet
Sominex max str 50 mg caplet0.27USD caplet
Benadryl allergy fastmelt tablet0.26USD tablet
Unisom 25 mg sleeptabs0.25USD tablet
Unisom 50 mg sleepgels0.25USD each
Unisom sleepmelts 25 mg tablet0.24USD tablet
Nytol 25 mg tablet0.23USD tablet
Benadryl allergy-sinus caplet0.22USD caplet
Compoz 25 mg gelcap0.2USD capsule
Benadryl allergy 25 mg softgel0.19USD softgel capsule
Benadryl allergy 25 mg ultratab0.19USD tablet
Benadryl allergy-cold kapgels0.19USD each
Benadryl allergy-sinus kapgels0.19USD each
Benadryl-d allergy-sinus ultratab0.19USD tablet
Diphenhydramine hcl powder0.17USD g
Eql allergy 25 mg tablet0.17USD tablet
Nighttime sleep aid 25 mg cplt0.17USD caplet
Banophen anti-itch 2% cream0.16USD g
Benadryl itch relief stick0.16USD ml
Sominex 25 mg tablet0.16USD tablet
Benadryl allergy 25 mg kapgels0.15USD each
Allergy 25 mg tablet0.14USD tablet
Benadryl 25 mg kapseals0.14USD each
Benadryl itch stopping crm0.14USD g
DiphenhydrAMINE HCl 25 mg capsule0.13USD capsule
Diphenhist with zinc cream0.12USD g
Ra allergy 25 mg tablet0.12USD tablet
CVS Pharmacy allergy 25 mg tablet0.11USD tablet
Diphenhydramine 25 mg minitab0.11USD tablet
Simply sleep 25 mg caplet0.11USD caplet
Sleep ii tablet0.11USD tablet
Diphenhydramine 50 mg capsule0.1USD capsule
Benadryl 2% spray0.09USD ml
Diphenhist 50 mg tablet0.09USD tablet
Genahist 25 mg tablet0.09USD tablet
Ra sleep tablet0.09USD tablet
Banophen 25 mg tablet0.08USD tablet
Wal-dryl anti-itch spray0.08USD ml
CVS Pharmacy allergy 25 mg caplet0.07USD caplet
Nighttime sleep aid 25 mg caplet0.07USD caplet
CVS Pharmacy itch relief spray0.06USD ml
Diphen 25 mg capsule0.06USD capsule
Diphenhist 25 mg caplet0.06USD caplet
Benadryl anti-itch 0.45% gel0.05USD g
Diphenhydramine 50 mg caplet0.05USD caplet
Benadryl itch stopping gel0.04USD g
Child benadryl-d aller-sin liquid0.04USD ml
Diphenhydramine 25 mg capsule0.04USD capsule
Vicks 44d cough & head liquid0.03USD ml
Vicks 44e cough & chest liquid0.03USD ml
Banophen allergy liquid0.02USD ml
Diphenhydramine 25 mg tablet0.02USD tablet
Ra anti-tussive dm syrup0.02USD ml
Siladryl 12.5 mg/5 ml liquid0.02USD ml
Silphen cough syrup0.02USD ml
Silphen dm cough syrup0.02USD ml
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Patent NumberPediatric ExtensionApprovedExpires (estimated)
US8883849No2002-01-172022-01-17Us
US9155718No2002-01-172022-01-17Us
US8263647No2002-05-302022-05-30Us

Properties

State
Solid
Experimental Properties
PropertyValueSource
melting point (°C)161-162Martin, H., Hafliger, F.,Gatzi, K.and Grob, A.; U.S. Patent 2,397,799; April 2,1946; assigned to J.R. Geigy AG, Switzerland. Rieveschl, G. Jr.; U.S. Patent 2,421,714; June 3,1947; assigned to Parke, Davis & Co. Rieveschl, G. Jr.; U.S. Patent 2,427,878; September 23,1947; assigned to Parke, Davis & Company.
boiling point (°C)150-165 °C at 2.00E+00 mm HgPhysProp
water solubility3060 mg/L (at 37 °C)BEILSTEIN
logP3.27HANSCH,C ET AL. (1995)
pKa8.98SANGSTER (1994)
Predicted Properties
PropertyValueSource
Water Solubility0.0752 mg/mLALOGPS
logP3.44ALOGPS
logP3.65ChemAxon
logS-3.5ALOGPS
pKa (Strongest Basic)8.87ChemAxon
Physiological Charge1ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area12.47 Å2ChemAxon
Rotatable Bond Count6ChemAxon
Refractivity79.93 m3·mol-1ChemAxon
Polarizability29.86 Å3ChemAxon
Number of Rings2ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+0.9898
Blood Brain Barrier+0.9381
Caco-2 permeable+0.8744
P-glycoprotein substrateSubstrate0.6211
P-glycoprotein inhibitor INon-inhibitor0.6632
P-glycoprotein inhibitor IINon-inhibitor0.8381
Renal organic cation transporterInhibitor0.7752
CYP450 2C9 substrateNon-substrate0.7897
CYP450 2D6 substrateSubstrate0.8919
CYP450 3A4 substrateSubstrate0.6173
CYP450 1A2 substrateInhibitor0.8306
CYP450 2C9 inhibitorNon-inhibitor0.9144
CYP450 2D6 inhibitorInhibitor0.8932
CYP450 2C19 inhibitorNon-inhibitor0.9039
CYP450 3A4 inhibitorNon-inhibitor0.934
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.7293
Ames testNon AMES toxic0.9132
CarcinogenicityNon-carcinogens0.6495
BiodegradationNot ready biodegradable0.9253
Rat acute toxicity2.7846 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.536
hERG inhibition (predictor II)Inhibitor0.6318
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)

Spectra

Mass Spec (NIST)
Not Available
Spectra
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSNot Available
GC-MS Spectrum - EI-BGC-MSsplash10-0a4i-9100000000-7b9eb1f702c76f6b6062
Mass Spectrum (Electron Ionization)MSsplash10-0a4i-9200000000-b9014c8fc8ccbba24163
MS/MS Spectrum - Quattro_QQQ 10V, N/ALC-MS/MSsplash10-0006-0090000000-a71e531b49571f09ab25
MS/MS Spectrum - Quattro_QQQ 25V, N/ALC-MS/MSsplash10-00kk-0980000000-cce91896f34562beeffa
MS/MS Spectrum - Quattro_QQQ 40V, N/ALC-MS/MSsplash10-001i-1900000000-4c29bd5e0eab94596eaa
MS/MS Spectrum - EI-B (Unknown) , PositiveLC-MS/MSsplash10-0a4i-9100000000-ab642e8f86de11af896c
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSNot Available
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSNot Available
LC-MS/MS Spectrum - LC-ESI-QFT , negativeLC-MS/MSsplash10-000t-0910000000-3576ca5ec77ab87354ec
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0900000000-0ccd6de9ca58593fd490
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0900000000-3568aae4c27ffe333c0e
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0900000000-22e0c745355c836f1535
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0900000000-6bb69a66a343440c64f8
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0900000000-1b87d83415d22bb17f1b
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0gb9-0900000000-50251362d768cd1b1c4f
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0gb9-0900000000-9f37a733a05f5b01d313
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-014i-0900000000-7d73b95ed09ea2d72260
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0gb9-2900000000-1666a8ab5a6d81c0bd01
LC-MS/MS Spectrum - LC-ESI-ITFT , positiveLC-MS/MSsplash10-014i-0900000000-3f31841d858381760f03
LC-MS/MS Spectrum - LC-ESI-ITFT , positiveLC-MS/MSsplash10-014i-0900000000-de872e048c7e12cef490
LC-MS/MS Spectrum - LC-ESI-ITFT , positiveLC-MS/MSsplash10-014i-0900000000-de872e048c7e12cef490
MS/MS Spectrum - , positiveLC-MS/MSsplash10-014i-0900000000-789a4a3fe118d5bf2456
MS/MS Spectrum - , positiveLC-MS/MSsplash10-014i-2900000000-8ef94659f614b9ff24ca
LC-MS/MS Spectrum - LC-ESI-QFT , positiveLC-MS/MSsplash10-0002-2950000000-7c7a9841f2f0b6428d69
1H NMR Spectrum1D NMRNot Applicable
[1H,13C] 2D NMR Spectrum2D NMRNot Applicable

Taxonomy

Description
This compound belongs to the class of organic compounds known as diphenylmethanes. These are compounds containing a diphenylmethane moiety, which consists of a methane wherein two hydrogen atoms are replaced by two phenyl groups.
Kingdom
Organic compounds
Super Class
Benzenoids
Class
Benzene and substituted derivatives
Sub Class
Diphenylmethanes
Direct Parent
Diphenylmethanes
Alternative Parents
Benzylethers / Trialkylamines / Dialkyl ethers / Organopnictogen compounds / Hydrocarbon derivatives
Substituents
Diphenylmethane / Benzylether / Tertiary aliphatic amine / Tertiary amine / Ether / Dialkyl ether / Organic nitrogen compound / Organic oxygen compound / Organopnictogen compound / Hydrocarbon derivative
Molecular Framework
Aromatic homomonocyclic compounds
External Descriptors
tertiary amino compound, ether (CHEBI:4636) / a small molecule (CPD-10890)

Targets

Details
1. Histamine H1 receptor
Kind
Protein
Organism
Human
Pharmacological action
Yes
Actions
Antagonist
General Function
Histamine receptor activity
Specific Function
In peripheral tissues, the H1 subclass of histamine receptors mediates the contraction of smooth muscles, increase in capillary permeability due to contraction of terminal venules, and catecholamin...
Gene Name
HRH1
Uniprot ID
P35367
Uniprot Name
Histamine H1 receptor
Molecular Weight
55783.61 Da
References
  1. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352]
  2. Piao H, Nagai S, Tsurumaki T, Niki T, Higuchi H: Potentiation by neuropeptide Y of histamine H1 receptor-mediated contraction in rat blood vessels. Vascul Pharmacol. 2007 Apr;46(4):260-70. Epub 2006 Oct 27. [PubMed:17169617]
  3. Kesiova M, Alexandrova A, Yordanova N, Kirkova M, Todorov S: Effects of diphenhydramine and famotidine on lipid peroxidation and activities of antioxidant enzymes in different rat tissues. Pharmacol Rep. 2006 Mar-Apr;58(2):221-8. [PubMed:16702624]
  4. Hasala H, Moilanen E, Janka-Junttila M, Giembycz MA, Kankaanranta H: First-generation antihistamines diphenhydramine and chlorpheniramine reverse cytokine-afforded eosinophil survival by enhancing apoptosis. Allergy Asthma Proc. 2007 Jan-Feb;28(1):79-86. [PubMed:17390763]
  5. Wang Z, Woolverton WL: Self-administration of cocaine-antihistamine combinations: super-additive reinforcing effects. Eur J Pharmacol. 2007 Feb 28;557(2-3):159-60. Epub 2006 Dec 1. [PubMed:17196194]
  6. Ishikawa T, Takechi K, Rahman A, Ago J, Matsumoto N, Murakami A, Kamei C: Influences of histamine H1 receptor antagonists on maximal electroshock seizure in infant rats. Biol Pharm Bull. 2007 Mar;30(3):477-80. [PubMed:17329841]
  7. Havas TE, Cole P, Parker L, Oprysk D, Ayiomamitis A: The effects of combined H1 and H2 histamine antagonists on alterations in nasal airflow resistance induced by topical histamine provocation. J Allergy Clin Immunol. 1986 Nov;78(5 Pt 1):856-60. [PubMed:2878016]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Antagonist
General Function
G-protein coupled acetylcholine receptor activity
Specific Function
The muscarinic acetylcholine receptor mediates various cellular responses, including inhibition of adenylate cyclase, breakdown of phosphoinositides and modulation of potassium channels through the...
Gene Name
CHRM2
Uniprot ID
P08172
Uniprot Name
Muscarinic acetylcholine receptor M2
Molecular Weight
51714.605 Da
References
  1. Liu H, Zheng Q, Farley JM: Antimuscarinic actions of antihistamines on the heart. J Biomed Sci. 2006 May;13(3):395-401. [PubMed:16453179]

Enzymes

Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
Inhibitor
General Function
Steroid hydroxylase activity
Specific Function
Responsible for the metabolism of many drugs and environmental chemicals that it oxidizes. It is involved in the metabolism of drugs such as antiarrhythmics, adrenoceptor antagonists, and tricyclic...
Gene Name
CYP2D6
Uniprot ID
P10635
Uniprot Name
Cytochrome P450 2D6
Molecular Weight
55768.94 Da
References
  1. Hamelin BA, Bouayad A, Drolet B, Gravel A, Turgeon J: In vitro characterization of cytochrome P450 2D6 inhibition by classic histamine H1 receptor antagonists. Drug Metab Dispos. 1998 Jun;26(6):536-9. [PubMed:9616188]
  2. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
  3. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256]
  4. Drug Interactions: Cytochrome P450 Drug Interaction Table [Link]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP1A2
Uniprot ID
P05177
Uniprot Name
Cytochrome P450 1A2
Molecular Weight
58293.76 Da
References
  1. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Steroid hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP2C9
Uniprot ID
P11712
Uniprot Name
Cytochrome P450 2C9
Molecular Weight
55627.365 Da
References
  1. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Steroid hydroxylase activity
Specific Function
Responsible for the metabolism of a number of therapeutic agents such as the anticonvulsant drug S-mephenytoin, omeprazole, proguanil, certain barbiturates, diazepam, propranolol, citalopram and im...
Gene Name
CYP2C19
Uniprot ID
P33261
Uniprot Name
Cytochrome P450 2C19
Molecular Weight
55930.545 Da
References
  1. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Steroid hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP2C18
Uniprot ID
P33260
Uniprot Name
Cytochrome P450 2C18
Molecular Weight
55710.075 Da
References
  1. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Steroid hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
CYP2B6
Uniprot ID
P20813
Uniprot Name
Cytochrome P450 2B6
Molecular Weight
56277.81 Da
References
  1. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Prostaglandin-endoperoxide synthase activity
Specific Function
Converts arachidonate to prostaglandin H2 (PGH2), a committed step in prostanoid synthesis. Involved in the constitutive production of prostanoids in particular in the stomach and platelets. In gas...
Gene Name
PTGS1
Uniprot ID
P23219
Uniprot Name
Prostaglandin G/H synthase 1
Molecular Weight
68685.82 Da
References
  1. Zhou SF, Zhou ZW, Yang LP, Cai JP: Substrates, inducers, inhibitors and structure-activity relationships of human Cytochrome P450 2C9 and implications in drug development. Curr Med Chem. 2009;16(27):3480-675. Epub 2009 Sep 1. [PubMed:19515014]

Transporters

Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Quaternary ammonium group transmembrane transporter activity
Specific Function
Mediates tubular uptake of organic compounds from circulation. Mediates the influx of agmatine, dopamine, noradrenaline (norepinephrine), serotonin, choline, famotidine, ranitidine, histamin, creat...
Gene Name
SLC22A2
Uniprot ID
O15244
Uniprot Name
Solute carrier family 22 member 2
Molecular Weight
62579.99 Da
References
  1. Urakami Y, Okuda M, Masuda S, Akazawa M, Saito H, Inui K: Distinct characteristics of organic cation transporters, OCT1 and OCT2, in the basolateral membrane of renal tubules. Pharm Res. 2001 Nov;18(11):1528-34. [PubMed:11758759]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Secondary active organic cation transmembrane transporter activity
Specific Function
Translocates a broad array of organic cations with various structures and molecular weights including the model compounds 1-methyl-4-phenylpyridinium (MPP), tetraethylammonium (TEA), N-1-methylnico...
Gene Name
SLC22A1
Uniprot ID
O15245
Uniprot Name
Solute carrier family 22 member 1
Molecular Weight
61153.345 Da
References
  1. Urakami Y, Okuda M, Masuda S, Akazawa M, Saito H, Inui K: Distinct characteristics of organic cation transporters, OCT1 and OCT2, in the basolateral membrane of renal tubules. Pharm Res. 2001 Nov;18(11):1528-34. [PubMed:11758759]
Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Inhibitor
General Function
Symporter activity
Specific Function
Sodium-ion dependent, high affinity carnitine transporter. Involved in the active cellular uptake of carnitine. Transports one sodium ion with one molecule of carnitine. Also transports organic cat...
Gene Name
SLC22A5
Uniprot ID
O76082
Uniprot Name
Solute carrier family 22 member 5
Molecular Weight
62751.08 Da
References
  1. Ohashi R, Tamai I, Nezu Ji J, Nikaido H, Hashimoto N, Oku A, Sai Y, Shimane M, Tsuji A: Molecular and physiological evidence for multifunctionality of carnitine/organic cation transporter OCTN2. Mol Pharmacol. 2001 Feb;59(2):358-66. [PubMed:11160873]

Drug created on June 13, 2005 07:24 / Updated on November 13, 2017 21:49